Telecommunications wire having a channeled dielectric insulator and methods for manufacturing the same

Abstract

The present disclosure relates generally to a telecommunications wire including an electrical conductor and a dielectric insulator surrounding the electrical conductor. The dielectric insulator defines a plurality of channels defining void space containing a material having a low dielectric constant such as air. The channels each run along a length of the electrical conductor. The channels are configured to lower an overall dielectric constant of the dielectric insulator while maintaining desirable mechanical properties such as crush resistance.

What is claimed is: 
     
       1. A method of manufacturing a telecommunications wire having a dielectric insulator with channels around an electrical conductor, the method comprising:
 providing an extrusion tip and an extrusion die with an annular extrusion passageway defined therebetween, wherein the extrusion tip defines an inner passageway; 
 providing a plurality of axial projections within the annular extrusion passageway with each axial projection defining an air passage, the plurality of axial projections configured to form the channels of the dielectric insulator; 
 passing flowable dielectric material through the annular extrusion passageway defined between the extrusion tip and the extrusion die to form a shaped dielectric material; 
 drawing air at atmospheric pressure into the air passages of the axial projections and directing the air at atmospheric pressure through the air passages in forming the channels; 
 in addition to drawing air at atmospheric pressure, directing pressurized air from a source of compressed air through the air passages of the axial projections and directing the pressurized air through the air passages in forming the channels; 
 passing an electrical conductor through the inner passageway defined by the extrusion tip; and 
 providing a first flow path in fluid communication with the source of compressed air for providing the pressurized air into the air passages and providing a second flow path in fluid communication with atmosphere for the drawing atmospheric air into the air passages, wherein the first flow path is separate from the second flow path. 
 
     
     
       2. A method according to  claim 1 , further comprising drawing down the shaped dielectric material upon the electrical conductor after the flowable dielectric material has been extruded. 
     
     
       3. A method according to  claim 2 , wherein the draw down ratio is at least 50 to 1. 
     
     
       4. A method according to  claim 3 , wherein the draw down ratio is at least 100 to 1. 
     
     
       5. A method according to  claim 4 , wherein the draw down ratio is at least 150 to 1. 
     
     
       6. A method according to  claim 1 , wherein the first flow path has a smaller transverse cross-sectional area from the second flow path. 
     
     
       7. A method according to  claim 1 , further comprising using a structure in the form of a truncated cone to funnel the flowable dielectric material into the annular extrusion passageway.